F⁺ Ion Implantation for Enhancing Surface Hydrophobicity of Medical Polymethylmethacrylate

The surface of medical polymethylmethacrylate intraocular lens was treated by F⁺ ion implantation at 80 keV with various doses. Hydrophobicity test showed that contact angle was increased from 68.5^º to 83.5^º with increasing dose. No appreciable changes in optical transparency and tensile strength were observed. X-ray photoelectron spectroscopy and electron spin resonance analysis indicated that F⁺ ion implantation broke some original O-containing groups to form some new C-F bond and radicals on the surface.